By Richard J. Chang

In 1996, Martine Rothblatt’s six-year-old daughter was diagnosed with pulmonary arterial hypertension, a rare lung and heart disease without a cure. Undeterred, Rothblatt, a cofounder of Sirius Satellite Radio, launched her own biotech firm with the goal of finding one.

“There is nothing worse than being told that your daughter is going to die,” Rothblatt told Forbes in 2018. “I just said I will find a way, or she was going to die, because all of the previous people with this illness had died.”

Nearly three decades later, Rothblatt’s daughter is healthy and in her 30s. Meanwhile, shares of the now publicly traded firm, United Therapeutics, are up 54 times its price at its 1999 IPO. This year alone, shares have surged, up 50% so far in 2024 and up 40% since April 30—enough to make Rothblatt the world’s newest billionaire.

The Silver Spring, Maryland-based business generated $2.1 billion in sales last year, largely from selling five FDA-approved drugs to help people like Rothblatt’s daughter treat pulmonary arterial hypertension (PAH). Investors have been cheering on United Therapeutics since it announced a $1 billion accelerated stock repurchase program in March, signaling it’s bullish about its pulmonary hypertension drugs. Also driving up the stock is excitement over the 41% year-over-year jump in revenue from its star drug, Tyvaso.

Rothblatt, 69, has led the now $14.7 billion (market capitalization) firm as CEO since she founded it. She has also been instrumental in helping push its subsidiary Revivicor into xenotransplantation, specifically manufacturing pig organs to transplant into humans with end-stage renal and cardiac diseases.

“There are tons of people on the waiting list for kidneys and hearts,” says Joseph Thome, senior research analyst at TD Cowen. “They’re willing to capitalize on it.”

No one has benefitted more financially from United Therapeutics’ success than Rothblatt, who has long been one of America’s wealthiest self-made women. Forbes’ pegged her net worth at $390 million in 2015, after the company found a successful treatment for PAH with Orenitram (“Martine Ro” spelled backwards). By 2021, with United Therapeutics stock on the rise, she was worth some $585 million. Now—given her 650,000 shares, plus options to acquire even more stock, cash accumulated over her decades in business, and houses in several states—Forbes estimates Rothblatt’s net worth has hit the $1 billion mark, making her one of just 35 self-made women billionaires in America.

It’s been a winding path to the three-comma club for Rothblatt. Born in San Diego in 1954, she hitchhiked the country playing music (she plays the piano, flute and drums) while studying communications at UCLA. A tour of a satellite facility in the Seychelles left her fascinated with the idea of using satellite networks to beam music to listeners around the world. After returning to the U.S., she got a joint law degree and MBA from UCLA and eventually took a gig as a telecommunications lawyer for a firm in Washington, D.C.

She cofounded Sirius Satellite Radio in 1990, helping to pioneer satellite-to-car broadcasting, and led its 1993 IPO. Three years later, doctors said her daughter had pulmonary arterial hypertension, or PAH, which at the time had a high mortality rate within two years of diagnosis. As many as 50,000 people in the U.S. have PAH, a progressive disease where abnormally high blood pressure affects the arteries in the lungs and heart. Rothblatt sold $3 million worth of SiriusXM stock and gave the money to doctors to come up with a treatment. When that didn’t work, she launched a company of her own—United Therapeutics—to find a cure. She took it public in 1999 in what was a $66 million IPO of a tiny biotech firm with $54,000 in revenue earned under an orphan drug grant from the FDA.

Three years later, United Therapeutics got approval for their first PAH treatment, Remodulin, in the U.S., Canada and Israel. The company created three other FDA-approved treatments for the disease, including one that is a once-daily pill. Then came Tyvaso, a treatment that relaxes blood vessels allowing blood to flow easier during exercise. In 2022, United Therapeutics gained approval for a dry powder formulation, called Tyvaso DPI, which comes in portable inhaler cartridges and helped push the company’s sales beyond $2 billion in 2023.

Earlier this year, investors worried that another PAH treatment, Merck’s Winrevair, would compete directly with Tyvaso, but Winrevair’s launch led to physicians to use both drugs in combination rather than only one treatment, says Ash Verma, executive director of biotech equity research at UBS.

“It’s a big moonshot, but it can be an attractive business,” Verma says. “There’s effectively no competition.”

Tyvaso is also in phase three trials as a treatment for idiopathic pulmonary fibrosis, a disease that causes scarring of the lungs. United Therapeutics announced that they expect data in the second half of 2025, earlier than investors initially projected.

In 2011, Rothblatt also steered into supplying lungs for organ transplants. United Therapeutics acquired xenotransplantation tech firm Revivicor (which created the first cloned mammal, Dolly the sheep) to develop organs raised in pigs. In 2022 and 2023, United Therapeutics led two successful transplants of hearts grown in genetically altered pigs. It announced the first successful transplant of one of their pig kidneys to a living human in April, and is spending $100 million on a new facility to further study the viability of xenotransplantation.

If United Therapeutics can succeed in saving lives with xenotransplantation, it would mark yet another milestone in a career filled with them for Rothblatt. Perhaps America’s best-known transgender CEO, she underwent gender reassignment surgery in 1994 and has spent decades as an advocate for LGBTQ rights, most notably speaking out against North Carolina’s controversial bathroom law in 2016. She is a licensed helicopter pilot who helped build the world’s first full-sized electric chopper and owns at least eight homes in four states.

A transhumanist, Rothblatt believes that someday people will be able to upload their minds to computers with the potential to create computer-run doppelgangers. She cofounded the Terasem Movement, a religious organization, in 2004 to propagate those ideas with her wife of 42 years, Bina (in whose image Rothblatt had built a humanoid head-and-shoulders robot).

It’s just one of many moonshot bets that have driven Rothblatt for decades to dive into everything from satellite radio to growing pig organs to help treat her daughter’s disease, making her a billionaire along the way.

“Instead of my daughter having no chance of getting an organ,” Rothblatt said in 2016, “there will be enough organs for everybody.”

Forbes